576 research outputs found

    Energy Consumption Rate based Stable Election Protocol (ECRSEP) for WSNs

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    In recent few yearsWireless Sensor Networks (WSNs) have seen an increased interest in various applications like border field security, disaster management and medical applications. So large number of sensor nodes are deployed for such applications, which can work autonomously. Due to small power batteries in WSNs, efficient utilization of battery power is an important factor. Clustering is an efficient technique to extend life time of sensor networks by reducing the energy consumption. In this paper, we propose a new protocol; Energy Consumption Rate based Stable Election Protocol (ECRSEP). Our CH selection scheme is based on the weighted election probabilities of each node according to the Energy Consumption Rate (ECR) of each node. We compare results of our proposed protocol with Low Energy Adaptive Clustering Hierarchy (LEACH), Distributed Energy Efficient Clustering (DEEC), Stable Election Protocol (SEP), and Enhanced SEP(ESEP). Our simulation results show that our proposed protocol, ECRSEP outperforms all these protocols in terms of network stability and network lifetime

    Throughput Enhancement of Restricted Access Window for Uniform Grouping Scheme in IEEE 802.11ah

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    IEEE 802.11ah has recently emerged as a promising standard for enabling massive machine-to-machine (M2M) communication. In order to support uplink data transmission from dense machine type clients (such as smart meters, IoT end nodes etc.), 802.11ah relies upon the restricted access window (RAW) based Medium Access Control (MAC) protocol. The underlying motivation behind this protocol is to reduce the contention for spectrum access among a large number of devices. The nodes contend with each other in their assigned RAW slot using Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA). In each RAW slot, the throughput depends upon the number of nodes. Current studies have suggested that the duration of each RAW slot should be the same in the entire RAW frame. However in this paper, we argue that the duration of each RAW slot should be chosen according to the size of the group. We present a model where a RAW frame is divided into two sub-frames and the duration of RAW slots in each sub-frame is chosen according to the size of the group. With the help of an analytical framework, we demonstrate that the throughput under our proposed scheme can be significantly enhanced when compared to a conventional implementation

    Frequency of Clinical Symptoms of Gastroesophageal Reflux Disease in Asthmatic Patients

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    Background: Gastroesophageal reflex is known as an acid reflex, is long term condition where stomach contents back into the oesophagus resulting in either symptoms or complications. GERD disease is caused by weakness or failure of the lower oesophageal sphincter. Symptoms include the acidic taste behind the mouth, heart burn, chest pain, difficult breathing and vomiting. Complication includes esophagitis, oesophageal strictures and barrettes oesophagus. Objective: The aim of this research was to introduce the symptoms of GERD disease in asthmatic patients and how these symptoms worsen the symptoms of asthma disease and what clinical pictures present with the asthmatic disease. Methodology: A designed performa was used to collect the data and after filling the performa, results were drawn and conclusion through the facts and the information given by patients. Results: In the present study among all 164 asthmatic patients, 70 (42.7%) patients showed dyspepsia, 58 (35.4%) were with chest burning, 23 (14%) were asking about chest pain, with acidic mouth taste were 39 (23.8%), 22 (13.4%) were feeling sore throat and 44 (26.8%) showed regurgitation reflex. Among these 164 patients 16 (9.8%) were smokers and 148 (90.2 %) were non-smokers. 47 (28.7%) were males and 117 (71.3%) were females. Conclusion: It is concluded that gastroesophageal reflux disease in asthmatic patients present symptoms of acidic mouth taste, chest burning, chest pain, dyspepsia, regurgitation reflex and sore throat

    Theoretical Investigation of the Deactivation of Ni Supported Catalysts for the Catalytic Deoxygenation of Palm Oil for Green Diesel Production

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    For the first time, a fully comprehensive heterogeneous computational fluid dynamic (CFD) model has been developed to predict the selective catalytic deoxygenation of palm oil to produce green diesel over an Ni/ZrO2 catalyst. The modelling results were compared to experimental data, and a very good validation was obtained. It was found that for the Ni/ZrO2 catalyst, the paraffin conversion increased with temperature, reaching a maximum value (>95%) at 300 °C. However, temperatures greater than 300 °C resulted in a loss of conversion due to the fact of catalyst deactivation. In addition, at longer times, the model predicted that the catalyst activity would decline faster at temperatures higher than 250 °C. The CFD model was able to predict this deactivation by relating the catalytic activity with the reaction temperature

    An overview of enhancing drought tolerance in cotton through manipulating stress resistance genes

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    Drought stress affects the normal growth of plant by influencing Physiological, morphological molecular and biochemical traits at cellular level. It is a polygenic trait, controlled by multiple genes, which makes its manipulation difficult by genetic engineering. It seems drought could be major threat in future to high yield of cotton in Pakistan as well around the globe because it is spontaneous and cannot be controlled with manuring and skilled agricultural practices. Gene manipulation could be a solution of this threat by producing transgenic cotton plants. As it is polygenic trait, so, understanding about cellular mechanism of drought tolerance is crucial to impart tolerance by controlling gene expression under stressed conditions. Universal Stress Proteins (USP) genes have already been identified in drought stressed leaves of Gossypium arboreum which make this variety of cotton a rich source of stress tolerance genes. USP genes could be manipulated for drought tolerant transgenic cotton with high yielding as well and it is most important family of proteins in this regard. This family encompasses a conserved group of proteins that has been reported in different organisms which are activating under various abiotic stress conditions. USP is also a regulatory protein; its activity can be increased by manipulating its interactions

    Piperlongumine nanoformulation attenuates pancreatic tumor desmoplasia and alter tumor immune responses

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    Pancreatic cancer (PanCa) is characterized by lack of early diagnosis, poor response to available therapeutic modalities and chemoresistance. Gemcitabine (GEM) is currently considered the most effective therapy for PanCa; however, it shows only a marginal survival benefit of 6 months. This poor drug response has been attributed to desmoplasia, causes suboptimal drug delivery, alters tumor microenvironment (TME), which includes tumor surrounding blood vessels, fibroblasts, immune cells, extracellular matrix, and other signaling molecules and induces chemo-resistance in tumors. To overcome these existing issues associated with chemotherapy, identification and development of novel therapeutic modalities are a pressing need. Piperlongumine (PL) is a natural alkaloid isolated from the long pepper, Piper longum L., and has shown substantial cancer-preventive and therapeutic efficacy against a variety of cancers. However, delivering its effective concentration in pancreatic tumors has been challenging. We have recently engineered a multi-layered Pluronic F127 and polyvinyl alcohol stabilized, and poly-L-lysine coated piperlongumine loaded poly(lactic-co-glycolic acid) nanoparticle formulation (PLGA-PL), which effectively inhibits the growth of PanCa cells. In this study, we demonstrate that PLGA-PL effectively sensitizes tumor cells to GEM via decreased desmoplasia, altered TME, SHH/CXCL12/CXCR4 and immune surveillance. Our finding show that PLGA-PL synergizes with GEM in inhibiting PanCa cell (HPAF-II and Panc-1) growth, migration, and invasion compared to free PL. Mechanistically, PLGA-PL targets the TME via inhibition of sonic hedgehog (SHH) pathway and oncogenic CXCR4/CXCL12 signaling axis that inhibits bidirectional tumor-stromal cells interaction. We have also found that PLGA-PL alone and in combination with GEM targets cancer stem cells by inhibiting pluripotency maintaining stemness factors (Nanog, Sox2, c-Myc, CD133, and Oct-4) as determined by qRT-PCR, Western blotting, and immunofluorescence analysis, and further confirmed by restricting tumor sphere formation. Furthermore, PLGA-PL also effectively targets tumor-associated macrophages (TAM) by repolarizing M2 into M1 phenotype via inhibiting expression of M2 markers and an increase in M1 markers in mouse macrophage cell line RAW264.7. M2 polarization of RAW264.7 cells were induced by culture with IL-4 (20 ng/mL) in presence of PLGA-PL or vehicle control. In addition, PLGA-PL effectively increases phagocytic capacity in murine macrophages as determined by phagocytosis assay (Vybrant Phagocytosis Assay Kit). In conclusion, we observed that PLGA-PL effectively targets TME, facilitates GEM uptake by inhibiting the activation of CXCR4/CXCL12/SHH signaling, and reprograming the tumor immune surveillance. This study suggests that PLGA-PL has great potential for future clinical use in management of PanCa

    Development and use of rectangular channels with a single current meter measurement for recording farm water deliveries (annexes)

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    Open channels / Calibrations / Measuring instruments / Flow measurement / Velocity / Pakistan

    Antioxidant and Antimutagenic Potential of Extracts of Some Agavaceae Family Plants

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    © 2016, Springer Science+Business Media New York.The application of natural antimutagens and antioxidants, particularly those derived from higher plants has been seen as a promising approach to the protection of human health. In this work, we studied methanolic extracts from Sansevieria cylindrica, Sansevieria trifasciata, and Polianthes tuberosa plants focusing on their antioxidative and antimutagenic capacities based on the following parameters: inhibitory activity on lipid peroxidation, suppressing ability on direct-acting mutagen sodium azide-induced mutagenesis in Salmonella typhimurium cells. A clear dose-dependent decrease in lipid peroxidation was observed with all the extracts tested. Extracts from leaves of P. tuberosa and rhizomes of S. cylindrica and S. trifasciata (1 mg/mL) displayed the highest antioxidant effect. At the same time, extracts from rhizomes of S. cylindrica and S. trifasciata significantly reduced the sodium azide-induced mutations. The highest antimutagenic activity (76 %) in the S. typhimurium TA100 strain was obtained for the S. cylindrica rhizomes extract (1 mg/plate). We propose that the observed protective effects of plant extracts tested may correspond to a synergic participation of several secondary metabolites and mainly to polyphenolic compounds

    The role of place branding and image in the development of sectoral clusters: the case of Dubai

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    This paper contextualizes how place branding and image influence the development of Dubai’s key sectoral clusters, including the key determinants of growth and success under the impression of Porter’s cluster theory. The approach is exploratory and of a qualitative inductive nature. Data was collected through conducting 21 semi-structured interviews with Dubai’s marketing/communication managers and stakeholders. Findings suggest that Dubai’s traditional clusters, namely, trading, tourism and logistics that have strong place branding and image show strong signs of success owing to Dubai’s geographical location (i.e., physical conditions). Among the new clusters, the financial sector is also benefitting from place branding. The results suggest that the success of traditional clusters have a positive spill over effect on the new clusters, in particular on construction and real estate. For policy makers it is worth to note that the recent success of the financial services cluster in Dubai will have positive impact on both, the traditional as well new clusters. The marketing and brand communication managers must consider the correlation and interplay of strength of activities amongst trading, tourism and logistics clusters and its implication while undertaking place branding for clients in their sector
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